| Procedure | Observation | Inference (Mark) | | :--- | :--- | :--- | | – Add NaOH dropwise then excess. | White precipitate formed, dissolved in excess NaOH. | Al³⁺ or Pb²⁺ or Zn²⁺ (1 mark for cation group). Confirm later. | | II. Confirm Pb²⁺ – Add KI solution. | Bright yellow precipitate. | Pb²⁺ confirmed (1 mark). | | III. Anion Test – Add dilute HCl to solid. | Effervescence (bubbles), gas turns limewater milky. | CO₃²⁻ (carbonate) (1 mark). | | IV. Sulfate test – Add BaCl₂ + HCl. | No white precipitate. | SO₄²⁻ absent (1 mark). | | V. Chloride test – Acidify with HNO₃, add AgNO₃. | White precipitate (curdy). | Cl⁻ present (1 mark). |
These are the most difficult marks to get if your practical technique is poor. In the 2006 titration question, if the examiner determined the "True Value" was 25.0 cm³, a student who got 25.0 cm³ to 25.1 cm³ would get full accuracy marks. A student with 24.5 cm³ kcse 2006 chemistry paper 3 marking scheme
Candidates were provided with to test for organic functional groups. | Procedure | Observation | Inference (Mark) |
The is a vital resource for students preparing for the Kenya Certificate of Secondary Education practical examination. As a practical paper, it tests a candidate’s ability to perform experiments, record accurate observations, and draw logical scientific inferences. Confirm later
The appearance of a permanent pink colour indicates the endpoint where all the analyte has reacted with the titrant. 2. Question 2: Inorganic Qualitative Analysis
Download the full official KCSE 2006 Chemistry Paper 3 Marking Scheme from KNEC portal or your school’s exam repository.